The present invention relates to a battery comprising a seal attached thereon which can be used for identifying the unused state of a battery, that is, whether the battery is new or old.
Hitherto, various methods have been devised for identifying the unused state, or the so-called virginity, of a battery.
For example, JP 52-72029, U discloses a sealing member for a positive electrode terminal surface comprising an insulating ring made of a thermoplastic synthetic resin with a L-shaped cross section, and a bridging band-like portion formed integrally with this.
However, there is a problem that this sealing member has a complex structure thereby making the integral formation step itself complicated. Additionally, there is another problem that the installation of the sealing member on the positive electrode terminal surface is relatively difficult. Further, this sealing member is not applicable to the negative electrode terminal surface.
Next, JP 54-48934, U discloses an old-or-new classification plate for dry batteries obtained by providing small pores on the periphery of the center of an insulating thin plate such as paper, and applying an adhesive on a portion thereof other than the center. Further, JP 58-169768, A discloses a sealing tape for dry batteries. This tape is obtained by applying an adhesive on one surface of a band-like tape body to cause a band-like film to adhere along the central portion of the resulting adhesive surface, causing the above film to adhere on a base and forming the above film such that the sealing tape located at the central portion of the tape body can be stripped off by providing slits.
However, the adhesives described in these publications are ones having the so-called adhesiveness, and applicable to both the positive electrode terminal surface and the negative electrode terminal surface; however there is a problem that they are inferior in terms of workability in adhesion.
In view of such problem in the past, an object of the present invention is to obtain a battery comprising an old-or-new identification seal attached thereon, which is applicable to both the positive electrode terminal and the negative electrode terminal and is simple in terms of the attaching operation.
The present invention provides a battery comprising an old-or-new identification seal made of an insulating base material having a heat sensitive adhesive layer, with the seal being attached on at least one of the positive electrode terminal and the negative electrode terminal via the adhesive layer.
It is preferable that the insulating base material is made of a heat-shrinkable resin film.
Also, it is preferable that the seal has an adhesive-free layer on a portion thereof in contact with the positive electrode terminal surface and/or the negative electrode terminal surface.
Also, it is effective that the battery is covered with a heat-shrinkable sheathing material and the old-or-new identification seal is formed integrally with the sheathing material.
Herein, xe2x80x9cterminal surfacexe2x80x9d in the present invention refers to the surface located on the outermost end portion of the terminal of the battery.